DataSource.Close()

function ds_callback(candle_idx)
   
end

function main()
   ds = CreateDataSource("TQBR", "SBER", INTERVAL_M1)
   if (ds == nil) then
      message("CreateDataSource returned nil")
   else
      r = ds:SetUpdateCallback(ds_callback)
      if (r == nil) then
         message("SetUpdateCallback returned nil")
      else
         if (r == false) then
            message("SetUpdateCallback returned false")
         end
      end
         
      while true do
         sleep(1000)
      end
   end
end

function OnStop(s)
   r = ds:SetEmptyCallback()
   if (r == nil) then
      message("SetEmptyCallback returned nil")
   else
      if (r == false) then
         message("SetEmptyCallback returned false")
      else
         r = ds:Close()
         if (r == nil) then
            message("Close returned nil")
         else
            if (r == false) then
               message("Close returned false")
            end
         end
      end
   end
end